Question: Even though this mystery bird was photographed on New Zealand, it is not native there. Where is this bird from? Can you identify its taxonomic family? Can you identify the species? This species shares an unusual character with amphibians: what might that be?

Response: This is an adult ostrich, Struthio camelus, an African bird. The ostrich is the largest member of the Struthionidae family -- indeed, it's the largest living bird in any avian family in the world.

Birds, such as the ostrich, that lack a keel on their sternum (and thus, lack an attachment point for their powerful flight muscles), are collectively known as ratites. The ratites are terrestrial flightless birds that often are very large. The taxonomic relationships amongst the ratites and between the ratites and other birds are controversial and somewhat confused, even with the advent of modern DNA technology. Currently, there are two ideas about how to classify these birds: the first method is based on the idea that the ratites evolved independently, so all ratite families are raised to the rank of taxonomic orders (resulting in a number of orders such as Struthioniformes, Rheiformes, Casuariformes, etc.) whilst the other idea is that ratites share a common ancestor so they all belong in one order: Struthioniformes.

The ostriches and other ratites share an unusual character with some amphibian species known as neoteny, which refers to the retention of juvenile characteristics in the adults of a species. In birds, neoteny includes soft, downy feathers, and underdeveloped wings. Interestingly, this condition occurs due to the lack of adequate thyroid hormone (hypothyroidism), a situation found in some amphibian species that also retain juvenile characters into adulthood. Experimentally thyroidectomised (thyroid gland removal) passerines retain juvenile characters, like soft, fluffy plumage, into adulthood just like ratites [DOI: 10.1111/j.1469-7998.1994.tb04618.x (abstract); here's a free PDF about neoteny and the thyroid in ratites that you might find interesting.]